Question

I’m using lxml in Python to parse some HTML and I want to extract all link to images. The way I do it right now is:

//a[contains(@href,'.jpg') or contains(@href,'.jpeg') or ... (etc)]

There are a couple of problem with this approach:

• you have to list all possible image extensions in all cases (both “jpg” and “JPG”), wich is not elegant
• in a weird situations, the href may contain .jpg somewhere in the middle, not at the end of the string

I wanted to use regexp, but I failed:

//a[regx:match(@href,'.*\.(?:png|jpg|jpeg)')]

This returned me all links all the time …

Does anyone knows the right, elegant way to do this or what is wrong with my regexp approach ?

Answer 1

Instead of:

a[contains(@href,'.jpg')]

Use:

a[substring(@href, string-length(@href)-3)='.jpg']

(and the same expression pattern for the other possible endings).

The above expression is the XPath 1.0 equivalent to the following XPath 2.0 expression:

a[ends-with(@href, '.jpg')]